Sales of Apple's iPhone accounted for more than 78 percent of smartphones sold at AT&T. The carrier said iPhone sales were "helped by AT&T's 4G network, which lets iPhone 4S download three-times faster than other U.S. carriers' networks."
Among the 4.3 million iPhones that AT&T sold in the first quarter of calendar 2012, 21 percent of those were new to AT&T. The total 5.5 million smartphones AT&T sold in the three-month period was a new record for the company.
AT&T's results compare to 3.2 million iPhones activated at rival carrier Verizon. The iPhone did not carry as large of a share at Verizon, though it still represented more than half of the 6.3 million smartphones sold during the quarter.
AT&T said on Tuesday that about 30 percent of its existing postpaid smartphone subscribers are on 4G-capable devices. Starting with the release of iOS 5.1, the iPhone 4S began advertising to users that they are on a "4G" network when utilizing AT&T's high-speed HSDPA network.
The change allowed AT&T to further differentiate itself from competitors Verizon and Sprint, which offer slower CDMA networks that cannot reach HSDPA speeds. However, "true" 4G remains exclusive to long-term evolution devices, such as Apple's third-generation iPad, which is the company's first LTE-capable product. AT&T made no mention of iPad sales in Tuesday's press release.
The new iPad comes in two different models that allow connectivity with Verizon and AT&T's respective LTE networks. The third-generation tablet also differentiates between AT&T's "4G" HSDPA and true LTE connectivity by displaying "LTE" on the device when connected to a high-speed 4G LTE network.
For the first quarter of calendar 2012, AT&T earned consolidated revenues of $31.8 billion, up $575 million, or 1.8 percent, compared to the same period a year ago. The carrier earned 60 cents diluted earnings per share, compared to 57 cents diluted EPS in the first quarter of 2011.